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Background: In patients with wheat-dependent exercise-induced anaphylaxis (WDEIA), anaphylactic shock occurs frequently, therefore avoidance of wheat products is recommended. We aimed to evaluate efficacy and safety of long-term omalizumab treatment for adult patients with WDEIA., Methods: In this phase 2, multicentre single-arm trial, 20 adult patients with WDEIA were enrolled (UMIN 000019250). All patients were administered 150-600 mg of omalizumab subcutaneously and evaluations (basophil activation and blood examination) were performed at regular intervals during administration period (0-48 weeks) and observation period (48-68 weeks). Primary endpoint was proportion of the patients who achieved a basophil activation rate below 10% with fractionated wheat preparations, and secondary endpoint was proportion of the patients with no allergic reactions after wheat products ingestion., Results: During the omalizumab treatment, more than 80% of the patients achieved the basophil activation rate less than 10% against all fractionated wheat preparations, and 68.8% of the patients who achieved the primary endpoint experienced no allergic reaction. During the observation period, the proportion of the patients who achieved a basophil activation rate below 10% decreased gradually, and the proportion of patients with positive allergic reactions increased gradually thereafter and reached maximum of 46.7%. Severe adverse events were not observed during the study., Conclusions: Long-term omalizumab treatment is safe and effective for adult patients with WDEIA when assessed by basophil activation rate with wheat allergens as well as allergic reactions after lifting of restrictions on wheat intake. However, this is not enough to achieve desensitization., (Copyright © 2023 Japanese Society of Allergology. Published by Elsevier B.V. All rights reserved.)

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a life-threatening food allergy triggered by wheat in combination with the second factor such as exercise. The identification of potential genetic risk factors for this allergy might help high-risk individuals before consuming wheat-containing food. We aimed to identify genetic variants associated with WDEIA. A genome-wide association study was conducted in a discovery set of 77 individuals with WDEIA and 924 control subjects via three genetic models. The associations were confirmed in a replication set of 91 affected individuals and 435 control individuals. Summary statistics from the combined set were analyzed by meta-analysis with a random-effect model. In the discovery set, a locus on chromosome 6, rs9277630, was associated with WDEIA in the dominant model (OR = 3.95 [95% CI, 2.31-6.73], p = 7.87 × 10 -8 ). The HLA-DPB1 ∗ 02:01:02 allele displayed the most significant association with WDEIA (OR = 4.51 [95% CI, 2.66-7.63], p = 2.28 × 10 -9 ), as determined via HLA imputation following targeted sequencing. The association of the allele with WDEIA was confirmed in replication samples (OR = 3.82 [95% CI, 2.33-6.26], p = 3.03 × 10 -8 ). A meta-analysis performed in the combined set revealed that the HLA-DPB1 ∗ 02:01:02 allele was significantly associated with an increased risk of WDEIA (OR = 4.13 [95% CI, 2.89-5.93], p = 1.06 × 10 -14 ). Individuals carrying the HLA-DPB1 ∗ 02:01:02 allele have a significantly increased risk of WDEIA. Further validation of these findings in independent multiethnic cohorts is needed., (Copyright © 2021 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Background: Food allergy is a growing health problem worldwide because of its increasing prevalence, life-threatening potential, and shortage of effective preventive treatments. In an outbreak of wheat allergy in Japan, thousands of patients had allergic reactions to wheat after using soap containing hydrolyzed wheat protein (HWP)., Objectives: The aim of the present study was to investigate genetic variation that can contribute to susceptibility to HWP allergy., Methods: We conducted a genome-wide association study of HWP allergy in 452 cases and 2700 control subjects using 6.6 million genotyped or imputed single nucleotide polymorphisms. Replication was assessed by genotyping single nucleotide polymorphisms in independent samples comprising 45 patients with HWP allergy and 326 control subjects., Results: Through the genome-wide association study, we identified significant associations with the class II HLA region on 6p21 (P = 2.16 × 10 -24 for rs9271588 and P = 2.96 × 10 -24 for HLA-DQα1 amino acid position 34) and with the RBFOX1 locus at 16p13 (rs74575857, P = 8.4 × 10 -9 ). The associations were also confirmed in the replication data set. Both amino acid polymorphisms (HLA-DQβ1 amino acid positions 13 and 26) located in the P4 binding pockets on the HLA-DQ molecule achieved the genome-wide significance level (P < 5.0 × 10 -8 )., Conclusions: Our data provide the first demonstration of genetic risk for HWP allergy and show that this genetic risk is mainly represented by multiple combinations of HLA variants., (Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Immediate-type wheat allergy due to hydrolyzed wheat protein (HWP-IWA) supplemented soap has been a serious social issue. We investigated the significance of challenge test and other tests not only to diagnose HWP-IWA but to know the symptoms of each patients., Methods: From January 2010 to June 2012, we performed challenge test in 41 cases with positive prick test of Glupearl 19S®, a major allergic HWP found in Cha no Shizuku®., Results: Thirty nine of 41 cases were challenge test positive. In two patients who showed positive skin prick test but negative for challenge test, titer of specific IgE antibody and/or basophil histamine release test against Glupearl 19S® revealed positive reaction., Conclusion: Challenge test is not included in indispensable examinations for the diagnosis of HWP-IWA in the recommended guidelines. However, challenge test is still a useful tool for assessing actual severity of each patient's symptoms and determining the timing of cessation of wheat avoidance. In addition, combined check-up with several laboratory examination and challenge test may help appropriate diagnosis of HWP-IWA.

Background: Recently, it has become a social problem that hydrolyzed wheat protein in facial soap can induce wheat allergy including wheat-dependent exercise-induced anaphylaxis (WDEIA). We described the clinical characteristics of the patients related., Methods: We collected 12 cases who had had a medical examination from January to October in 2010., Result: All the patients were female and mean age was 36.0± 9.9 years. All of them had had no prior symptoms history of wheat allergy, they gradually developed wheat anaphylaxis or WDEIA in an average of 2 years after they started to use a soap product in question which contains hydrolyzed wheat proteins. Most patients suffered immediate contact allergic reactions after or at the time of washing their face with the soap product. 10 of 12 patients showed a low level of IgE to CAP-recombinant ω-5-gliadin. Episodes of anaphylaxis were prevented by avoiding both intake of wheat-containing foods and usage of the soap product., Conclusion: We concluded that their wheat anaphylaxis is likely to be caused by epicutaneous sensitization of the hydrolyzed wheat proteins in the soap product. It was important that physicians should know the possibility of sensitization from non-dietary antigen.